The present invention relates, in general, to electronics, and more particularly, to vacuum microelectronic devices.
In the past, various semiconductor manufacturing techniques were used to make vacuum microelectronic devices such as field emission displays. Semiconductor manufacturing techniques were utilized because of the small geometries and spacing of the vacuum microelectronic devices. Typically, line widths of less than twenty microns and line spacing of less than thirty microns were required. Critical dimensions (CD) including layer to layer registration or inter-layer alignment, such as registration between two metal layers, required tolerances of less than one micron. Semiconductor exposing, developing, etching, patterning, and deposition techniques such as stepper exposing, RIE etching, and CVD deposition typically were used to form successive layers from the same surface of the substrate in order to achieve the desired line spacing and widths.
One disadvantage of using semiconductor manufacturing techniques is cost. A substrate for a vacuum microelectronic device often requires an area equal to or even greater than that of an entire semiconductor wafer. The high manufacturing costs made the vacuum microelectronic device too costly to manufacture.
Accordingly, there is a need to have a low cost method of forming a vacuum microelectronic device that achieves the required line spacing and widths.